US20020037033A1 - Serialised test of parallel optical module - Google Patents

Serialised test of parallel optical module Download PDF

Info

Publication number
US20020037033A1
US20020037033A1 US09956866 US95686601A US2002037033A1 US 20020037033 A1 US20020037033 A1 US 20020037033A1 US 09956866 US09956866 US 09956866 US 95686601 A US95686601 A US 95686601A US 2002037033 A1 US2002037033 A1 US 2002037033A1
Authority
US
Grant status
Application
Patent type
Prior art keywords
channel
test pattern
defined
system
digital communications
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US09956866
Inventor
Jan During
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Microsemi Semiconductor AB
Original Assignee
Microsemi Semiconductor AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B10/00Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00Arrangements for detecting or preventing errors in the information received
    • H04L1/20Arrangements for detecting or preventing errors in the information received using signal quality detector
    • H04L1/203Details of error rate determination, e.g. BER, FER or WER

Abstract

A method and system for measuring performance characteristics such as bit error rate (BER) in a multiple parallel-channel digital communications system. A transmitter such as a VCSEL array outputs multiple, high data rate, digital signals onto an appropriate media for reception at a receiving end. The test architecture uses a test pattern generator at the transmitter end and a data re-shaper connected to a receiver in each channel. The output of each re-shaper is serially connected back into the next channel transmitter until each channel has been tested. An error detector connected serially to the last receiver provides an evaluation of the characteristics of the multiple channels.

Description

    FIELD OF THE INVENTION
  • This invention relates to digital communications systems and more particularly to methods and systems for efficiently measuring performance characteristics in multiple, parallel-channel optical transceivers. [0001]
  • BACKGROUND
  • Ongoing developments in the field of information technology and in particular multimedia applications have resulted in considerable growth in broadband systems with the resulting demand to increase network data rates. The high speed capabilities of optical devices, including vertical cavity surface emitting lasers (VCSELs) have made such devices prime candidates for delivering high data rate signals. One application for such devices is in a multiple, parallel channel architecture wherein data is input on parallel links and transmitted over a transmission media to a receiver at the destination end. The digitized data is transported over such transmission media as optical fibers, twisted pairs, co-axial cables or for short distances through the air. For optical fibers and for transmission through the air, optical energy from the optical devices is modulated directly to provide an efficient data transmitter. In the more conventional twisted pair or coaxial cables the optical signal is converted to an electrical signal and carried over electrical conductors to the destination. [0002]
  • Due to the miniaturization possible with optical sources, such as VCSELs, multiple transmitters can be used in a parallel architecture wherein each link or channel carries different data streams. [0003]
  • Since optical transmitters, and indeed all components in a transmission system including receivers and transceiver architectures, are subject to numerous sources of variation it is frequently desirable and indeed necessary to test the digital parallel links both on initialization and periodically during operation. A typical test set up for a single channel includes a pattern generator to produce a digital test pattern which is provided to a transmitter, passed through the transmission media to a receiver and subsequently tested using an error detector at the receiver end. Typically, when conducting parallel bit error rate measurements on a parallel transmitter module with multiple channels, a separate pattern generator is required for each channel and a separate error detector for each channel is situated at the receiver end. This test architecture necessitates excessive use of resources as a separate pattern generator and a separate error detector is required for each channel. Additionally, the testing of each channel is done separately which for a multiple channel structure can result in considerable testing time. [0004]
  • Accordingly, there is a need for an improved method and system for measuring system parameters in a multiple, parallel channel digital communications network. [0005]
  • SUMMARY OF THE INVENTION
  • The present invention seeks to address the above identified problem by minimizing test equipment and decreasing the test times for transmission system measurements. [0006]
  • Therefore, in accordance with a first aspect of the present invention there is provided a method of testing performance characteristics of a digital communications system having N parallel channels, the method comprising: providing a test pattern to a transmitter and transmitting the test pattern over a first channel; receiving and reshaping the test pattern; serially re-transmitting the reshaped test pattern over a second channel; repeating steps b) and c) up to channel N-[0007] 1; re-transmitting the reshaped test pattern over channel N to a receiver; and evaluating the received reshaped test pattern.
  • In accordance with second aspect of the invention there is provided a system for testing performance characteristics of a digital communications system having N parallel channels, the system comprising: a test pattern generator to generate a test pattern; a parallel transmitter to transmit the test pattern sequentially over each of the multiple channels beginning with the first channel; a receiver in each channel for receiving the test pattern; a data re-shaper in each channel up to channel N-[0008] 1 and connected serially to the receiver for reshaping the received test pattern; means to serially provide the reshaped test pattern to the parallel transmitter for transmission over subsequent channels up to channel N; and an error detector serially connected to the receiver in channel N for evaluating the received test pattern.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • The invention will now be described in greater detail with reference to the attached drawings wherein: [0009]
  • FIG. 1 is a block diagram of a circuit for bit error rate measurements of a single channel transmitter module; [0010]
  • FIG. 2 is a block diagram of a parallel bit error rate measurement of a parallel transmitter module with N channels; and [0011]
  • FIG. 3 is a block diagram of a serialized bit error rate measurement of a parallel transmitter module with N channels according to the present invention.[0012]
  • DETAILED DESCRIPTION OF THE INVENTION
  • FIG. 1 provides a block diagram of the system architecture used for measuring performance characteristics, such as bit error rate, of a single channel transmitter module. A transmitter [0013] 10 which may be, for example, a single element VCSEL receives a test signal from pattern generator 14. The transmitter outputs the optical signal over a transmission media that may be, for example, an optical fiber cable or an air link. If an alternate media such as a twisted pair or coaxial cable is used the transmitter will include a converter to convert the optical signal to an electrical signal prior to being transmitted through the media. At receiver 18 the optical signal is received and converted to an electrical signal. If the received signal is already in an electrical form it is received and amplified as is well known. An error detector 20 is used at the output of the receiver to test characteristics such as bit error rate, jitter etc.
  • FIG. 2 illustrates a system for testing system characteristics of transmission architecture having multiple channels with a parallel transmitter for outputting individual channels onto each link. As shown the system includes channels [0014] 1 to N each having its own pattern generator and its own error detector.
  • FIG. 3 is a block diagram of a serialized bit error rate measurement of a parallel transmitter module again with N channels according to a preferred aspect of the present invention. As shown in FIG. 3 a single pattern generator and a single error detector are required. Each channel, however, is provided with a data re-shaper that is serially connected to the receiver. The reshape circuit is required in as much as the signal tends to degrade as it passes through a channel or link. Without the reshape circuit it is possible that the signal will degrade to the point that the error detector at the end of the serialized link can't reliably detect the data in the test pattern generated by the pattern generator. [0015]
  • As shown in FIG. 3, the pattern generator provides a test signal to the parallel transmitter that outputs the signal on the first channel. The test signal is then transmitted over the media to the receiver and then data reshaped. The output of the data re-shaper is fed back serially to channel [0016] 2 and the process continues sequentially through each channel to N-1 with the output of a data re-shaper at N-1 coupled back into channel N. The output of the transmitter associated with channel N is received and subsequently fed to the error detector to perform the requested test procedure.
  • With the test set up as shown in FIG. 3 it is possible to make a bit error measurement for a parallel optical module simultaneously on each channel. [0017]
  • The system can be used to conduct various test measurements such as bit error rate testing measurements, jitter measurements, eye diagram measurements and combinations of these various measurements. [0018]
  • As shown in FIG. 3 the system includes a transmitter and a receiver but it is to be understood that the test procedure can be used to test individually, digital parallel transmitters, digital parallel receivers as well as digital parallel transceivers. [0019]
  • While specific embodiments of the invention have been described and illustrated it will be apparent to one skilled in the art that numerous alternatives and variations can be implemented without departing from the basic concept of the invention. It is to be understood, however, that such alternatives and variations will fall within the true scope of the invention as defined in the appended claims. [0020]

Claims (16)

  1. 1. A method of testing performance characteristics of a digital communications system having N parallel channels, the method comprising:
    a) providing a test pattern to a transmitter and transmitting the test pattern over a first channel;
    b) receiving and reshaping the test pattern;
    c) serially re-transmitting the reshaped test pattern over a next channel;
    d) repeating steps b) and c) up to channel N-1;
    e) re-transmitting the reshaped test pattern over channel N to a receiver; and
    f) evaluating the received, reshaped test pattern.
  2. 2. The method as defined in claim 1 for serially measuring bit error rates (BER) in a multiple parallel-channel digital communications system.
  3. 3. The method as defined in claim 1 for serially measuring jitter in a multiple parallel-channel digital communications system.
  4. 4. The method as defined in claim 1 for serially measuring eye diagrams in a multiple parallel-channel digital communications system.
  5. 5. The method as defined in claim 1 for serially measuring combinations of bit error rates, jitter and eye diagrams in a multiple parallel-channel digital communications system.
  6. 6. The method as defined in claim 1 for testing performance of transmitters in a multiple parallel-channel digital communications system.
  7. 7. The method as defined in claim 1 for testing performance of receivers in a multiple parallel-channel digital communications system.
  8. 8. The method as defined in claim 1 for testing performance of transceivers in a multiple parallel-channel digital communications system.
  9. 9. A system for testing performance characteristics of a digital communications system having N parallel channels, the system comprising:
    a) a test pattern generator to generate a test pattern;
    b) a parallel transmitter to transmit a test pattern generated by said test pattern generator sequentially over each of the multiple channels beginning with the first channel;
    c) a receiver in each channel for receiving the test pattern;
    d) a data re-shaper in each channel up to channel N-1 and connected serially to the receiver for reshaping the received test pattern;
    e) means to serially provide the reshaped test pattern to the parallel transmitter for transmission over subsequent channels up to channel N; and
    f) an error detector serially connected to the receiver in channel N for evaluating the received test pattern.
  10. 10. The system as defined in claim 9 for testing performance characteristics of transmitters in a multiple parallel-channel digital communications system.
  11. 11. The system as defined in claim 9 for testing performance characteristics of receivers in a multiple parallel-channel digital communications system.
  12. 12. The system as defined in claim 9 for testing performance characteristics of transceivers in a multiple parallel-channel digital communications system.
  13. 13. The system as defined in claim 9 wherein said error detector has means to measure bit error rates (BERs).
  14. 14. The system as defined in claim 9 wherein said error detector has means to measure jitter.
  15. 15. The system as defined in claim 9 wherein said error detector has means to measure eye diagrams.
  16. 16. The system as defined in claim 9 wherein said error detector has means to measure combinations of BER, jitter and eye diagrams.
US09956866 2000-09-22 2001-09-21 Serialised test of parallel optical module Abandoned US20020037033A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB0023245A GB2367220B (en) 2000-09-22 2000-09-22 Serialised test of parellel optical module
GB0023245.4 2000-09-22

Publications (1)

Publication Number Publication Date
US20020037033A1 true true US20020037033A1 (en) 2002-03-28

Family

ID=9899915

Family Applications (1)

Application Number Title Priority Date Filing Date
US09956866 Abandoned US20020037033A1 (en) 2000-09-22 2001-09-21 Serialised test of parallel optical module

Country Status (5)

Country Link
US (1) US20020037033A1 (en)
CA (1) CA2357193A1 (en)
DE (1) DE10144117A1 (en)
FR (1) FR2814615A1 (en)
GB (1) GB2367220B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030229830A1 (en) * 2002-06-06 2003-12-11 Ingo Thiele Method for the dynamic control of the channel use of a transmission channel and a load generator for sending a test sequence
US20050100336A1 (en) * 2003-11-06 2005-05-12 Mendenhall Scott N. Method and system for measuring optical properties of a medium using digital communication processing techniques
US20070247191A1 (en) * 2006-03-30 2007-10-25 Nec Corporation Pre-emphasis automatic adjusting method and data transmission system using same
US20080016404A1 (en) * 2006-06-30 2008-01-17 Masakazu Ishikawa Communication Control System and Communication Control Method
US20090208219A1 (en) * 2008-02-15 2009-08-20 Mark Rhodes Multimode Communications System
US8903326B2 (en) 2010-11-15 2014-12-02 Apple Inc. Simultaneous downlink testing for multiple devices in radio-frequency test systems

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3986168A (en) * 1975-06-02 1976-10-12 Ncr Corporation Multichannel error signal generator
US4887309A (en) * 1987-07-16 1989-12-12 Telefonaktiebolaget L M Ericsson Optical repeater for fault tracing in an optical transmission system
US5044707A (en) * 1990-01-25 1991-09-03 American Bank Note Holographics, Inc. Holograms with discontinuous metallization including alpha-numeric shapes
US5128779A (en) * 1988-02-12 1992-07-07 American Banknote Holographics, Inc. Non-continuous holograms, methods of making them and articles incorporating them
US5142383A (en) * 1990-01-25 1992-08-25 American Banknote Holographics, Inc. Holograms with discontinuous metallization including alpha-numeric shapes
US5145212A (en) * 1988-02-12 1992-09-08 American Banknote Holographics, Inc. Non-continuous holograms, methods of making them and articles incorporating them
US5761216A (en) * 1995-02-24 1998-06-02 Advantest Corp. Bit error measurement system
US6108801A (en) * 1998-08-11 2000-08-22 Cisco Systems, Inc. Using profiles to perform Bit Error Rate Testing
US6137830A (en) * 1998-01-16 2000-10-24 Motorola Measuring bit error rate performance of a receiver by the receiver and conveying measurement acoustically
US6584592B2 (en) * 1998-06-16 2003-06-24 Mitsubishi Denki Kabushiki Kaisha Semiconductor testing apparatus for testing semiconductor device including built in self test circuit
US6816987B1 (en) * 2000-03-25 2004-11-09 Broadcom Corporation Apparatus and method for built-in self-test of a data communications system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4791653A (en) * 1987-08-25 1988-12-13 Hewlett-Packard Company Pseudorandom word sequence synchronizer
JPH0918410A (en) * 1995-06-26 1997-01-17 Fujitsu Ltd Monitoring device for wavelength multiplex optical communication
FR2738433B1 (en) * 1995-08-30 1997-11-14 Trt Telecom Radio Electr transmission system comprising a test circuit

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3986168A (en) * 1975-06-02 1976-10-12 Ncr Corporation Multichannel error signal generator
US4887309A (en) * 1987-07-16 1989-12-12 Telefonaktiebolaget L M Ericsson Optical repeater for fault tracing in an optical transmission system
US5128779A (en) * 1988-02-12 1992-07-07 American Banknote Holographics, Inc. Non-continuous holograms, methods of making them and articles incorporating them
US5145212A (en) * 1988-02-12 1992-09-08 American Banknote Holographics, Inc. Non-continuous holograms, methods of making them and articles incorporating them
US5411296A (en) * 1988-02-12 1995-05-02 American Banknote Holographics, Inc. Non-continuous holograms, methods of making them and articles incorporating them
US5044707A (en) * 1990-01-25 1991-09-03 American Bank Note Holographics, Inc. Holograms with discontinuous metallization including alpha-numeric shapes
US5142383A (en) * 1990-01-25 1992-08-25 American Banknote Holographics, Inc. Holograms with discontinuous metallization including alpha-numeric shapes
US5761216A (en) * 1995-02-24 1998-06-02 Advantest Corp. Bit error measurement system
US6137830A (en) * 1998-01-16 2000-10-24 Motorola Measuring bit error rate performance of a receiver by the receiver and conveying measurement acoustically
US6584592B2 (en) * 1998-06-16 2003-06-24 Mitsubishi Denki Kabushiki Kaisha Semiconductor testing apparatus for testing semiconductor device including built in self test circuit
US6108801A (en) * 1998-08-11 2000-08-22 Cisco Systems, Inc. Using profiles to perform Bit Error Rate Testing
US6816987B1 (en) * 2000-03-25 2004-11-09 Broadcom Corporation Apparatus and method for built-in self-test of a data communications system

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030229830A1 (en) * 2002-06-06 2003-12-11 Ingo Thiele Method for the dynamic control of the channel use of a transmission channel and a load generator for sending a test sequence
US7114107B2 (en) * 2002-06-06 2006-09-26 Tektronix International Sales Gmbh Method for the dynamic control of the channel use of a transmission channel and a load generator for sending a test sequence
US20050100336A1 (en) * 2003-11-06 2005-05-12 Mendenhall Scott N. Method and system for measuring optical properties of a medium using digital communication processing techniques
WO2005047871A2 (en) * 2003-11-06 2005-05-26 Itt Manufacturing Enterprises, Inc. Method and system for measuring optical properties of a medium using digital communication processing techniques
WO2005047871A3 (en) * 2003-11-06 2005-09-22 Itt Mfg Enterprises Inc Method and system for measuring optical properties of a medium using digital communication processing techniques
US20100070199A1 (en) * 2003-11-06 2010-03-18 Itt Manufacturing Enterprises, Inc. Method and system for measuring optical properties of a medium using digital communication processing techniques
US7616888B2 (en) * 2003-11-06 2009-11-10 Itt Manufacturing Enterprises, Inc. Method and system for measuring optical properties of a medium using digital communication processing techniques
US7995917B2 (en) * 2003-11-06 2011-08-09 Itt Manufacturing Enterprises, Inc. Method and system for measuring optical properties of a medium using digital communication processing techniques
US20090161790A1 (en) * 2006-03-30 2009-06-25 Nec Corporation Pre-emphasis automatic adjusting method and data transmission system using same
US7489738B2 (en) * 2006-03-30 2009-02-10 Nec Corporation Pre-emphasis automatic adjusting method and data transmission system using same
US8243845B2 (en) 2006-03-30 2012-08-14 Nec Corporation Pre-emphasis automatic adjusting method and data transmission system using same
US20070247191A1 (en) * 2006-03-30 2007-10-25 Nec Corporation Pre-emphasis automatic adjusting method and data transmission system using same
US7873871B2 (en) * 2006-06-30 2011-01-18 Hitachi, Ltd. Communication control system and communication control method
US20080016404A1 (en) * 2006-06-30 2008-01-17 Masakazu Ishikawa Communication Control System and Communication Control Method
US20090208219A1 (en) * 2008-02-15 2009-08-20 Mark Rhodes Multimode Communications System
US8903326B2 (en) 2010-11-15 2014-12-02 Apple Inc. Simultaneous downlink testing for multiple devices in radio-frequency test systems

Also Published As

Publication number Publication date Type
DE10144117A1 (en) 2002-04-18 application
CA2357193A1 (en) 2002-03-22 application
FR2814615A1 (en) 2002-03-29 application
GB0023245D0 (en) 2000-11-01 grant
GB2367220B (en) 2004-02-18 grant
GB2367220A (en) 2002-03-27 application

Similar Documents

Publication Publication Date Title
US6614236B1 (en) Cable link integrity detector
US6678319B1 (en) Digital signal processing for high-speed communications
US8143900B2 (en) Communication system fault location using signal ingress detection
US5969836A (en) Method and apparatus for simultaneous transmission of digital telephony and analog video over a single optic fiber using wave division multiplexing
US5796502A (en) Multiple independent/dependent monochromatic light frequency fiber optic communication system and method
US6356369B1 (en) Digital optical transmitter for processing externally generated information in the reverse path
US5063612A (en) Network transceiver
US20060200708A1 (en) System and method for network error rate testing
US6075634A (en) Gigabit data rate extended range fiber optic communication system and transponder therefor
US4301536A (en) Multitone frequency response and envelope delay distortion tests
US6032185A (en) Bus network with a control station utilizing tokens to control the transmission of information between network stations
US6700875B1 (en) System, device, and method for selecting a channel in a multichannel communication network
US4564933A (en) Supervision of digital transmission systems
US7016308B1 (en) Digital return path for hybrid fiber/coax network
US7257328B2 (en) System and method for transmitting data on return path of a cable television system
US20050089334A1 (en) Protocol independent managed optical system
US6580535B1 (en) Polarization division multiplexing in optical data transmission systems
US6069876A (en) Performance monitoring of an ATM Network
US6025949A (en) Line monitoring of an optical transmission system using pilot signals
US6446867B1 (en) Electro-optic interface system and method of operation
US20040208523A1 (en) Swept frequency reflectometry using an optical signal with sinusoidal modulation
US20020054648A1 (en) Method for equalizing channel quality differences in a WDM system
US20070166042A1 (en) Multiservice optical communication
US7209667B2 (en) Methods of connecting and testing interfaces for CWDM fiber-optic systems
US5790286A (en) Technique for embodying duplication of optical paths in optical data transmission

Legal Events

Date Code Title Description
AS Assignment

Owner name: ZARLINK SEMICONDUCTOR AB, SWEDEN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DURLING, JAN;REEL/FRAME:012198/0693

Effective date: 20010917

AS Assignment

Owner name: ZARLINK SEMICONDUCTOR AB, SWEDEN

Free format text: RE-RECORD TO CORRECT THE NAME OF THE ASSIGNOR, PREVIOUSLY RECORDED AT REEL 012198, FRAME 0693.;ASSIGNOR:DURING, JAN;REEL/FRAME:012371/0673

Effective date: 20010917